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-rw-r--r--fs/btrfs/extent-tree.c82
1 files changed, 53 insertions, 29 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 53026806ae9e..4aedbff36b8f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4911,6 +4911,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
u64 bytenr;
u64 generation;
u64 refs;
+ u64 flags;
u64 last = 0;
u32 nritems;
u32 blocksize;
@@ -4948,15 +4949,19 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
generation <= root->root_key.offset)
continue;
+ /* We don't lock the tree block, it's OK to be racy here */
+ ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
+ &refs, &flags);
+ BUG_ON(ret);
+ BUG_ON(refs == 0);
+
if (wc->stage == DROP_REFERENCE) {
- ret = btrfs_lookup_extent_info(trans, root,
- bytenr, blocksize,
- &refs, NULL);
- BUG_ON(ret);
- BUG_ON(refs == 0);
if (refs == 1)
goto reada;
+ if (wc->level == 1 &&
+ (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ continue;
if (!wc->update_ref ||
generation <= root->root_key.offset)
continue;
@@ -4965,6 +4970,10 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
&wc->update_progress);
if (ret < 0)
continue;
+ } else {
+ if (wc->level == 1 &&
+ (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ continue;
}
reada:
ret = readahead_tree_block(root, bytenr, blocksize,
@@ -4988,7 +4997,7 @@ reada:
static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
- struct walk_control *wc)
+ struct walk_control *wc, int lookup_info)
{
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
@@ -5003,8 +5012,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
* when reference count of tree block is 1, it won't increase
* again. once full backref flag is set, we never clear it.
*/
- if ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
- (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag))) {
+ if (lookup_info &&
+ ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
+ (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
BUG_ON(!path->locks[level]);
ret = btrfs_lookup_extent_info(trans, root,
eb->start, eb->len,
@@ -5065,7 +5075,7 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
static noinline int do_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
- struct walk_control *wc)
+ struct walk_control *wc, int *lookup_info)
{
u64 bytenr;
u64 generation;
@@ -5085,8 +5095,10 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
* for the subtree
*/
if (wc->stage == UPDATE_BACKREF &&
- generation <= root->root_key.offset)
+ generation <= root->root_key.offset) {
+ *lookup_info = 1;
return 1;
+ }
bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
blocksize = btrfs_level_size(root, level - 1);
@@ -5099,14 +5111,19 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
- if (wc->stage == DROP_REFERENCE) {
- ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
- &wc->refs[level - 1],
- &wc->flags[level - 1]);
- BUG_ON(ret);
- BUG_ON(wc->refs[level - 1] == 0);
+ ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
+ &wc->refs[level - 1],
+ &wc->flags[level - 1]);
+ BUG_ON(ret);
+ BUG_ON(wc->refs[level - 1] == 0);
+ *lookup_info = 0;
+ if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level - 1] > 1) {
+ if (level == 1 &&
+ (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ goto skip;
+
if (!wc->update_ref ||
generation <= root->root_key.offset)
goto skip;
@@ -5120,12 +5137,17 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
wc->stage = UPDATE_BACKREF;
wc->shared_level = level - 1;
}
+ } else {
+ if (level == 1 &&
+ (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
+ goto skip;
}
if (!btrfs_buffer_uptodate(next, generation)) {
btrfs_tree_unlock(next);
free_extent_buffer(next);
next = NULL;
+ *lookup_info = 1;
}
if (!next) {
@@ -5148,21 +5170,22 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
skip:
wc->refs[level - 1] = 0;
wc->flags[level - 1] = 0;
+ if (wc->stage == DROP_REFERENCE) {
+ if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
+ parent = path->nodes[level]->start;
+ } else {
+ BUG_ON(root->root_key.objectid !=
+ btrfs_header_owner(path->nodes[level]));
+ parent = 0;
+ }
- if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
- parent = path->nodes[level]->start;
- } else {
- BUG_ON(root->root_key.objectid !=
- btrfs_header_owner(path->nodes[level]));
- parent = 0;
+ ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
+ root->root_key.objectid, level - 1, 0);
+ BUG_ON(ret);
}
-
- ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
- root->root_key.objectid, level - 1, 0);
- BUG_ON(ret);
-
btrfs_tree_unlock(next);
free_extent_buffer(next);
+ *lookup_info = 1;
return 1;
}
@@ -5276,6 +5299,7 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
struct walk_control *wc)
{
int level = wc->level;
+ int lookup_info = 1;
int ret;
while (level >= 0) {
@@ -5283,14 +5307,14 @@ static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
btrfs_header_nritems(path->nodes[level]))
break;
- ret = walk_down_proc(trans, root, path, wc);
+ ret = walk_down_proc(trans, root, path, wc, lookup_info);
if (ret > 0)
break;
if (level == 0)
break;
- ret = do_walk_down(trans, root, path, wc);
+ ret = do_walk_down(trans, root, path, wc, &lookup_info);
if (ret > 0) {
path->slots[level]++;
continue;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 17:51:47 +0100